This invention relates to copying and duplicating devices and more particularly to such devices wherein recording is accomplished by means of a non-contact jet drop print head. A number of such devices are shown in the prior art as disclosed, for instance in Ranger et al U.S. Pat. No. 1,817,098, Behane et al U.S. Pat. No. 3,604,846 and Loughren U.S. Pat. No. RE27,555. Each of these supports a copy sheet on a rotating drum, across which a jet drop print head is translated. A somewhat different arrangement is disclosed in Taylor U.S. Pat. No. 3,564,120 wherein a plurality of jet drop print heads are scanned in rotary arcs over a print receiving paper being transported in a horizontal plane. These prior art devices are configured in such a manner as to be generally adapted for use in an office copying or duplicating environment, but they are all considered to be too slow for most office copying applications.
A faster copier is taught in Cahill et al U.S. Pat. No. 3,689,693 wherein a plurality of print heads, typically eight, cooperatively print stripes collectively representing an original to be reproduced. This reduces the printing time significantly, but the system is somewhat limited by the fact that it has only one printing nozzle per head. An even faster printing employs multiple nozzle heads which print interlaced helical tracks as taught in Van Hook U.S. Pat. No. 4,009,332. Finally of general background interest for their showing of other different types of jet drop copiers are Hertz U.S. Pat. No. 3,416,153, Suenaga U.S. Pat. No. 3,553,371, Wick et al U.S. Pat. No. 3,828,355 and Fishbeck U.S. Pat. No. 3,925,790.